The assembly of a semiconductor package plays an important role in semiconductor fabrication and thermal management. A conventional semiconductor package includes a lid, one or more die, seal adhesive, interconnects, a substrate, and/or a thermal interface material (TIM).
The die is placed on the substrate through a die-attach process. Typically, the die-attach process involves attaching a flip-chip type die to the substrate by interconnects through a reflow process. In a lid attach process, the seal adhesive is dispensed on a periphery of the substrate by a needle-type dispensing head, for example, for attaching the lid later. The TIM is applied to a bottom side of the die (i.e., the side opposite the interconnects) by the needle-type dispensing head. An underfill may be applied to the interconnects, the die, and the substrate to at least reduce stress to the semiconductor package. The lid is thereafter placed on the substrate, typically making contact with the seal adhesive and the die by way of the TIM.
In the conventional lid attach process, the needle-type dispensing head is often used for both dispensing the seal adhesive and the TIM. The seal adhesive and TIM are typically contained in a container such as a flask or vial and dispensed through tubes in the needle-type dispensing head by capillary action. There are disadvantages, however in dispensing either the seal adhesive or TIM via the needle-type dispensing head process. For large or small die applications, the throughput can be reduced due to the time needed to apply complicated TIM dispensing patterns to the die. FIG. 1 is a plan view of a semiconductor package undergoing a stage of fabrication where a complicated dispensing pattern 10 has been applied to a top of the die 20. Further, the seal adhesive may be improperly dispensed on the substrate. These may cause voids on the substrate or the seal adhesive may shift from the correct dispensing pattern 10 thereby compromising the integrity of the semiconductor package. FIG. 1 shows an example of seal adhesives 30 applied on the periphery of substrate 70 and a seal adhesive 40 that has shifted from its intended location 50. Further still, in the needle-type dispensing process, the dispensing pattern and weight may be difficult to control leading to insufficient TIM coverage on the die or insufficient adhesive coverage on the substrate.